Yellow fog warning issued for 12 Irish counties overnight

Motorists face hazardous conditions as fog rolls in overnight

The status yellow alert covers 12 counties and comes into effect at 9pm on Sunday, lasting until 11am the following day. 

Forecasters expect thick patches of fog to form after sunset, with visibility potentially becoming very poor in some locations.

The affected counties are Donegal, Cavan, Monaghan, Louth, Meath, Westmeath and Longford, along with all five counties in Connacht: Galway, Leitrim, Mayo, Roscommon and Sligo.

This is the second fog warning issued within a day. Saturday's alert covered 25 counties across the Republic, excluding only Donegal.

No equivalent warning has been issued by the UK Met Office.

A mostly dry Sunday will make way for heavy rain this week

A status yellow warning is used when conditions pose a risk in certain areas, even if the weather is not particularly unusual overall.

The Irish Times quoted the warning definition as saying that "weather conditions are not especially unusual, but where danger exists in localised areas."

Although Sunday is expected to stay mostly dry once early mist and fog clear, conditions will become wetter at the start of the week. 

Rain is forecast to move north from the south on Monday night, followed by heavier downpours on Tuesday and Wednesday. Brighter, cooler weather should return towards the weekend.

With fog expected to overlap with Monday's morning traffic, drivers are being advised to allow extra time and prepare for sudden changes in visibility along their routes.